Heat Holders Women's Thermal Stripe Socks Size 5-9 US 91% Acrylic, 5% Nylon, 3% Polyester, 1% Elastane machine wash Heat Holders Yarn - Heat Holders' Specially developed thermal yarn provides high performance insulation against cold with superior moisture breathing abilities. Heat Holders Loops - Innovative knitting Technology produces our unique, extra long looped cushion pile to hold in more warm air, increasing the TOG rating. Heat Holders Brushing - Finally, our expert brushing process maximises the amount of warm air held inside each sock for total warmth and all day comfort. Heat Holders are Scientifically tested to be over 7x warmer than a basic cotton sock! Heat Holders Tog rating being 2.34 whilst a basic cotton sock only measures at 0.33 Tog. Heat Holders' ladies comes in a bunch of fabulous colors so that you can combine warmth, comfort and style into one ultimate package